Plastic recycling process
AssigneeImpact Laboratories Ltd.
InventorsThomas Rose, Steven Burns, Emmeline Aves, Andrew West
Life of this patent
Estimating the term…
Abstract
A process for the extraction of one or more colour pigments from waste plastic in which a waste plastic feedstock is mixed with a solvent in a reactor having a shearing mechanism and the solvent is separated out and recycled in the process. The shearing mechanism provides high shear, high contact mixing so as to move the pigment to the surface of the plastic for contact with the solvent to give efficient colour pigment removal. Embodiments of reactors with shearing mechanisms are described. Environmentally friendly solvents are also described. The process gives highly sought after natural recyclate at a commercial scale.
Claims12
A process for the extraction of one or more colour pigments from coloured waste plastic, the process comprising:
- (a) introducing a coloured waste plastic feedstock to a reactor;
- (b) introducing a solvent to the reactor, wherein the solvent comprises an ionic liquid;
- (c) mixing the coloured waste plastic with the solvent in the reactor so as to extract at least one colour pigment by contact with the solvent, wherein the coloured waste plastic feedstock is heated to melt the plastic;
- (d) removing the solvent and extracted pigment from the reactor;
- (e) separating the solvent from the extracted pigment;
- (f) collecting the extracted pigment;
- and
- (g) collecting colourless plastic with the at least one colour pigment removed;
- characterised in that:
- the coloured waste plastic is plastic in which the entire plastic is compounded with the at least one colour pigment when the plastic is manufactured and the at least one colour pigment is intertwined with polymer molecules;
- separated solvent is re-introduced to new coloured waste plastic feedstock at step (b);
- and
- in step (c) a shear mechanism is used to increase the contact between the one or more colour pigments and the solvent by compressing the mix and re-orientating plastic particles to bring the at least one colour pigment to a surface of the plastic for exposure to the solvent.
A process for the extraction of one or more colour pigments from coloured waste plastic, the process comprising:
- (a) introducing a coloured waste plastic feedstock to a reactor;
- (b) introducing a solvent to the reactor, wherein the solvent copmrises an ionic liquid;
- (c) mixing the coloured waste plastic with the solvent in the reactor so as to extract at least one colour pigment by contact with the solvent;
- (d) removing the solvent and extracted pigment from the reactor;
- and (d)
- (e) collecting colourless plastic with the at least one colour pigment removed;
- characterised
- in that:
- the coloured waste plastic is plastic in which the entire plastic is compounded with the at least one colour pigment when the plastic is manufactured and the at least one colour pigment is interwined with polymer molecules;
- step (c) comprises mixing the coloured waste plastic as a melt with the solvent;
- and
- in step (c) a shear mechanism is used to increase the contact between the one or more colour pigments and the solvent.
Dependencies are inferred from the claim text.